1. Field of the Invention
This invention relates to the adjustment of wheels and more specifically to the truing of bicycle tire rims wherein the rims are supported by spokes.
2. Description of the Prior Art
It has long been a problem with all wheels having rims supported by spokes to maintain the rim in a true or a straight position and in the proper roundness. Because of the lightness of the rims and the nature of spoke-type construction, the rims are susceptible to transverse deformation and deformation of the roundness.
Attempts have been made in the past to provide an effective and relatively easy means of "truing" rims; in other words, aligning the rim by manipulation of the spokes until the rim is perfectly round and lies in a flat plane. A non-true rim produces increased wobble as the spin of the wheel increases, affects steering control, increases wear on the tire and generally has an overall deleterious effect on the operation and performance of the bicycle.
Nothing in the prior art, alone or in combination, is thought to teach or suggest the portable truing system of the present invention. Relevant patents are as follows:
Jackman, U.S. Pat. No. 451,053, discloses a tire gauge for determining wear on tires. The instrument finds the location and extent of wear of a tire. The invention includes a sliding rod having a hooked upper end terminating at a point that contacts the surface tire. The other end of the rod is attachable to the axle of the wheel. Also included is an adjusting screw that provides a means for maintaining the rod parallel to the side of the wheel. When it is determined that the tire is worn to a certain state, the tire may be removed and trued.
Greenleaf. et al., U.S. Pat. No. 2,402,041, discloses a wheel attachment of checking wheel-roll of multi-wheeled vehicles. The attachment includes a body with an opening therein which may be attached on the axis of the wheel. The body is supported from the ground by means of a wheel connected to the body by a bracket and by a tracer wheel.
Mielewerke, German Patent No. 492,815 discloses a stationary device for checking the contour of a spoked wheel.